Research Interest and Area of R&D Activities

Prof. Tripathi has made notable contributions by identifying and characterizing nitrogen-fixing bacteria which support the growth of important grasses that inhabit desiccating desert (Sewan grass or d conditions in lakes and ponds (deep water rice) using cultivation-dependent and cultivation independent molecular techniques. He was also the first from India to show the occurrence of Ralstonia (renamed as Cupriavidus, a β-rhizobium) as microsymbiont colonizing the legume nodules (Mimosa pudica and other species). Focussing his research on a carotenoid-producing, non-photosynthetic, plant growth promoting rhizobacterium, he unravelled the role of alternative sigma factors, anti-sigma factors and bacteriophytochrome in Azospirillum brasilense in mediating its response to abiotic stresses including photooxidative stress. He showed that two pairs of ECF sigma factors (RpoE) and ZAS anti-sigma factors (ChrR) control photodynamic stress response in A. brasilense. Occurrence of cross-talk between two pairs of non-cognate sigma factors and ZAS anti-sigma factors that affects redox homeostasis is the first report by him in any bacterial system. He found a novel regulatory cascade consisting of RpoE1 and RpoH2 sigma factors that controls carotenogenesis in A. brasilense. He has also identified several novel salt-stress-induced genes and promoters in A. brasilense. Using 16S rDNA-based cultivation-independent methods, he identified, for the first time, the microbes associated with methanogenesis in an Indian coalbed, His current researches are focussed on understanding the systems biology of A. brasilense for its synthetic biology towards efficient carbon sequestration, and for developing A. brasilense mutants as microbial cell factory for producing secondary metabolites of pharmaceutical importance.